1. Field of the Invention
The present invention relates to a plate for a heat exchanger, and more particularly, to a plate for a heat exchanger, which has beads of refrigerant distributing sections formed asymmetrically and streamlined beads arranged in the same number on flow channels in the form of a zigzag so that refrigerant flowing inside a tank is distributed and introduced to tubes uniformly, thereby increasing a heat radiation amount and enhancing a heat exchange efficiency by forming uniform flow distribution and reducing a pressure drop of refrigerant, and miniaturizing the heat exchanger into a compact size.
2. Background Art
In general, a heat exchanger refers to a device in which a flow channel for heat exchange medium so that heat exchange medium exchanges heat with external air while being circulated through the flow channel. The heat exchanger is used in various air conditioning devices, and is employed in various forms such as a fin tube type, a serpentine type, a drawn cup type and a parallel flow type according to various conditions in which it is used.
The heat exchanger has an evaporator using refrigerant as heat exchange medium, which is divided into one-tank, two-tank and four-tank types:
In the one-tank type heat exchanger, tubes formed by coupling two one-tank plates each having a pair of cups formed at one end thereof and a U-shaped channel defined by a partitioning bead disposed therein are laminated alternately with heat radiation fins.
In the two-tank type heat exchanger, tubes formed by coupling two two-tank plates each having cups respectively formed at the top and bottom thereof are laminated alternately with heat radiation fins.
In the four-tank type heat exchanger, tubes formed by coupling two four-tank plates each having cup pairs formed at the top and bottom thereof and two channels divided by a separator are laminated alternately with heat radiation fins.
Hereinafter, for convenience, the one-tank type heat exchanger will be described as an example.
As shown in FIGS. 1 to 3, the heat exchanger 1 includes: a plurality of laminated tubes 10 formed by coupling two plates 11, each tube having a pair of cups 14 formed at the top or the top and bottom thereof side by side and respectively having slots 14a and a U-shaped channel 12 for fluidically communicating the tanks 40 defined by a partitioning bead 13 vertically formed between the tanks 40 to a predetermined length; heat radiation fins 50 laminated between the tubes 10; and two-end plates 30 mounted at the outermost sides of the tubes 10 and the radiation fins 50 to reinforce them.
In addition, both plates 11 facing to each other are embossed and so a plurality of inward-projected first beads 15 of the plates 11 are bonded, so that a turbulent flow of refrigerant is formed in the flow channel 12 of the tube 10.
Further, in the each tube 10, the flow channel 12 has refrigerant distributing sections 16 formed on inlet and outlet sides thereof, in which each refrigerant distributing section 16 has a plurality of passageways 16b partitioned by a plurality of second beads 16a so that refrigerant is uniformly distributed into the flow channel 12.
In addition, since the double head plate is substantially same as the single head plate 11 except that two cups are provided in the bottom end of the double head plate, hereinafter only the single head plate 11 having two cups 14 formed on the top end will be illustrated for the sake of convenience.
The tubes 10 also include manifold tubes 20 projecting to sides of the tanks 40, in which one of the manifold tubes 20 has an inlet manifold 21 connected with an inlet pipe 2 for introducing refrigerant and manifold tubes 20a projecting to the other sides of the tanks 40, in which one of the manifold tubes 20a has an outlet manifold 21a connected with an outlet pipe 3 for discharging refrigerant.
The manifolds 21 and 21a are constructed of a circular pipe type formed by contacting two manifold plates respectively having semi-circular manifolds 21 and 21a. The manifolds 21 and 21a are combined with the inlet pipe 2 and the outlet pipe 3 by a brazing material of a ring type, and then, the manifolds 21 and 21a, the inlet pipe 2 and the outlet pipe 3 are combined with one another by brazing.
Moreover, the manifold tubes 20 and 20a are the same as the tubes 10 except the manifolds 21 and 21a. 
As described above, referring to FIG. 1, a flow of refrigerant inside the heat exchanger 1 will be described as follows.
The tanks 40 having the inlet manifold 21 and the outlet manifold 21a of the refrigerant further include baffles 60 formed therein for partitioning introduced refrigerant and discharge refrigerant from each other.
Therefore, based on the baffles 60, the tanks 40 are divided into an inlet side 4 for introducing refrigerant and an outlet side 5 for discharging refrigerant, the tank 40 of the inlet side 4 is designated as “A” and “B” parts and the tank 40 of the outlet side 5 for discharging refrigerant is designated as “C” and “D” parts in the drawing.
When being introduced through the inlet side manifold 21, refrigerant is uniformly distributed in the A part of the tank 40 and flows along the U-shaped flow channels 12 of the tubes 10 and 20. In succession, refrigerant is introduced into the B part of the adjacent tank 40, and then flows into the C part of the same tank 40. Refrigerant flows again along the U-shaped flow channels 12 of the tubes 10 and 20a, and then, is introduced into the D part of the tank 40 having the outlet manifold 21a to be finally discharged to the outside.
During the process that refrigerant circulating inside a cooling system along a refrigerant line is introduced and discharged, the heat exchanger 1 exchanges heat with the air blown between the tubes 10, 20 and 20a and evaporates refrigerant, whereby the air blown out to the inside of the automobile is cooled by a heat absorption action via evaporation latent heat of refrigerant.
Recently, with a compact and small-size oriented trend of the heat exchanger 1, the heat exchanger 1 has to be provided with structure and performance satisfying high efficiency and low refrigerant pressure drop. Particularly, in case of the refrigerant pressure drop, since the heat exchanger 1 is gradually narrowed, if the heat exchanger 1 is manufactured by plates of the existing form, it may cause increase in work of the compressor (not shown) and decrease of system efficiency due to high refrigerant pressure drop.
That is, the prior art heat exchanger includes the first beads 15 formed at regular intervals along the flow channels 12 and bonded with each other to enhance heating efficiency and secure durability of the heat exchanger 1, and the refrigerant distributing sections 16 having the second beads 16a formed at regular intervals to uniformly distribute refrigerant stored in the tank 40 to the flow channels 12 and securing durability.
However, like the prior art plate 11, if the first beads 15 and the second beads 16a formed on the refrigerant distributing sections 16 are formed at regular intervals symmetrically, as shown in FIG. 4, refrigerant may form ununiform flow distribution, and thereby, a heat radiation amount and a heat exchange efficiency are reduced, and so, it is difficult to miniaturize the heat exchanger into a compact size.
That is, in FIG. 4, a red color indicates a part where refrigerant of great flux flows fast, and a green color indicates a part where refrigerant of small flux flows slowly.
Therefore, when we see the whole flow of the plate, the plate 11 has another problem in that refrigerant flux is small at the center in a width (lateral) direction and high at both sides, and when we see the just flow of the refrigerant distributing section, there is a problem in that refrigerant of great flux flows at the center of the refrigerant distributing sections 16 but refrigerant of small flux flows ununiformly since the speed of refrigerant current is gradually slower toward both sides of the refrigerant distributing sections 16.
Furthermore, the plate 11 has another problem in that refrigerant of great flux flows and is crowded when refrigerant is more distant from the refrigerant distributing sections 16 in a longitudinal (vertical) direction of the plate 11.
As described above, the prior art plate 11 generally shows the ununiform refrigerant flow distribution in all directions.